[HBASE-26524] Support remove coprocessor by class name via alter table command

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.0.0-alpha-2
• Fix Version/s: 3.0.0-alpha-2
• Component/s: Coprocessors, shell
• Labels: incompatible incompatibleChange
• Hadoop Flags: Incompatible change, Reviewed

Release Note

This is an incompatible change for TableDescriptorBuilder#removeCoprocessor, if coprocessor does not exist and removeCoprocessor is being called, the new behavior is emitting an IllegalArgumentException instead of previously do nothing

From now on, alter command introduces a new method table_remove_coprocessor that operator can remove table coprocessor by class name. Please see the usage as below

* remove a single table coprocessor
alter 't1', METHOD => 'table_remove_coprocessor', CLASSNAME => 'org.apache.hadoop.hbase.coprocessor.SimpleRegionObserver'

* remove multiple coprocessors
alter 't1', METHOD => 'table_remove_coprocessor', CLASSNAME => ['org.apache.hadoop.hbase.coprocessor.SimpleRegionObserver', 'org.apache.hadoop.hbase.coprocessor.Export']

• Tags: incompatible
• Assignee: Tak-Lon (Stephen) Wu
• Reporter: Tak-Lon (Stephen) Wu
• Created: 01/Dec/21 05:10
• Updated: 15/Apr/22 23:28
• Resolved: 06/Dec/21 22:19

Description

With the shell, when operator wants to remove a table coprocessor, the flow is to

1. first use decs find the the mapping of coprocessor$# e.g. coprocessor$1, where # is the ordered number when the coprocessor was internally added to the table attribute
2. issue table_att_unset with the target `coprocessor$#` that maps to a value that include the unique class name.

This task is to simplify the flow if the operator know exactly the class name of the added coprocessor, and create a new sub-method to alter, such that operator can do it only with the class name.

NOTE that this logic has been added behind the scenes at TableDescriptorBuilder#removeCoprocessor for removing `ConstraintProcessor` , and we are just exposing this logic with a new method to alter command.

Issue Links

• is related to: HBASE-26530 Backport HBASE-26524 Support remove coprocessor by class name via alter table command
• relates to: HBASE-26957 Add support to hbase shell to remove coproc by its class name instead of coproc ID
• relates to: HBASE-26529 Document HBASE-26524 to section of Dynamic Unloading
• links to: GitHub Pull Request #3902
• links to: GitHub Pull Request #3912
• links to: https://github.com/apache/hbase/pull/3912